cmd/gopherbot: wait for information longer on CherryPickCandidate issues

We've started using WaitingForInfo to identify backport issues that
don't need to be reviewed because they're waiting on information.

Unlike normal issues, this information can reasonably need more than
a month to become available. Avoid the toil of reopening such backport
requests each month by extending its deadline.

Change-Id: Id2d07f228003dae2032942c0129e162797d4f58d
Reviewed-on: https://go-review.googlesource.com/c/build/+/511637
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Carlos Amedee <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Run-TryBot: Dmitri Shuralyov <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>

Author: dmitshur

cmd/gopherbot/gopherbot.go

@@ -1253,6 +1253,11 @@ func (b *gopherbot) closeStaleWaitingForInfo(ctx context.Context) error {
 			}
 
 			deadline := waitStart.AddDate(0, 1, 0) // 1 month
+			if gi.HasLabel("CherryPickCandidate") {
+				// Cherry-pick candidates may sometimes need to wait for fixes
+				// to soak on the order of months, so give them more time.
+				deadline = waitStart.AddDate(0, 6, 0)
+			}
 			if now.Before(deadline) {
 				return nil
 			}